1. Field of the Invention
This invention relates generally to structures and systems that are designed to selectively shelter or cover a surface or a space. Without limitation, such a system or structure may be embodied as a roof, a partition, a wall panel, façade, shade or awning. The invention is particularly suitable for large outdoor sheltering or covering systems.
2. Description of the Related Technology
The concept of a structure or system for selectively covering a surface or a space has been known since time immemorial, and is embodied in structures as varied as household window shades and awnings to retractable covers for stadiums and manufacturing facilities. A covering system may be designed for indoor use or for outdoor use, and may include a solid sheltering surface, a flexible sheltering surface such as a fabric material or a combination of such elements.
A covering system that utilizes a flexible sheltering surface such as a fabric material tends to possess advantages over a system that has a solid sheltering surface, such as reduced fabrication costs, reduced weight and the ability to require less space when it is not being deployed. However, a number of technical problems have made it difficult to deploy large, outdoor covering systems that utilize a flexible sheltering surface such as a fabric material. For purposes of this document, a large outdoor covering system is a system that has a sheltering surface that is at least substantially 500 ft.2. Such large covering systems present technical and engineering design challenges that do not exist in smaller covering systems. Accordingly, engineering solutions that have been successfully applied to smaller systems are not necessarily transferable to large covering systems.
For example, strong winds can cause an outdoor fabric covering system to become unstable, particularly if the fabric material is not adequately tensioned. Heavy snow can also cause the fabric material to sag or tear if the fabric material is not adequately supported and tensioned. While motorized systems for deploying a fabric covering system exist, the force requirements for adequately tensioning a large fabric covering system would have required a drive mechanism so robust and bulky that the system would have been uneconomical and unwieldy. Moreover, the typical motorized deployment system for a fabric covering system is not capable of tensioning the fabric cover in more than one direction.
A need exists for a large outdoor flexible covering system that is economical to construct and deploy, that provides superior weather resistance and that is capable of tensioning the flexible sheltering surface in more than one direction.